

var regExp = new RegExp("[a-z]{5}\\d{3}");
var reg = /[a-z]{5}\d{3}/;

let str = "123abibabcde123";

// console.log(reg.exec(str));

// console.log(reg.test(str));


// 英文字母开头 + 数字
let usernameReg = /^[A-z]+\d*/;


console.log("a123456".match(usernameReg));
console.log(usernameReg.test("123456"));



